Stopcocks are a common and essential component of medical infusion equipment as they allow the linking of tubes of an infusion system to different inlet or outlet tubes. Such stopcocks, which may be made of plastic, glass or metal, typically comprise an outer tubular body provided with two or more luer type connectors and, rotatable therein, a solid core member provided with bores adapted to come into register with the lumen of the luer connectors and allow transfer of fluid from one connector to another. The core member is connected or integral with a handle which allows the user to select between different states.
Luer connectors in medical devices must conform with international standards as regards their inner and outer dimensions. This limits their lumen diameter to a maximum of about 3.0 mm, which in turn limits the maximum flow rate. In various medical procedures in which a slow fluid flow rate is required, this is not a serious handicap, whereas in others this fact is disadvantageous necessitating use of various other accessories. In laparoscopic surgery, for example, a body cavity, e.g. the peritoneum, is first inflated with a gas such as CO.sub.2 which process is termed "insuffiation". Insufflation is a rather slow process, in contrast the release of the gas from the body cavity, which process is termed "disufflation", which is usually a very fast process, lasting a few seconds. In principle, conventional stopcocks could be used for such a procedure, i.e. the connector connected to the duct leading to the body cavity (the "body duct"), being linked to a connector connected to the duct leading to the gas source (the "gas duct") during insufflation, and switched so as to be linked to an opening from which the gas is discharged (the "gas discharge opening"), during disufflation; however, the diameter of the lumen of the luer connector of conventional stopcocks as well as the diameter inside the core member of conventional stopcocks, is unduly limiting the rate flow of the same during the disufflation step, and therefore, conventional stopcocks are not used or used only to a limited extent in such a procedure.